Revolving fan.



0. S. JENNINGS.

REVOLV ING FAN. APPLICATION FILED JAN. 6| I915.

Patented May 15, 1917.

2 SHEETS-SHEET I.

ATTORNEY 0. 3. JENNINGS. REVOLVING FAN.

APPLICATION FILED JAN- 6,1915.

Patented May15, 1917 2 SHEETS-SHEET 2.

INVENTOR "rinrrnn l ia itdihl OLIVER S. JENNINGS, OF WILKINSBURG,PENNSYLVANIA, ASSIGNOR T0 WESTING- HOUSE ELECTRIC AND MANUFACTURINGCOMPANY, A. CORPORATION OF PENN- SYLVANIA.

REVOLVING FAN.

Specification of Letters Patent.

Patented May 15, 191?.

To (MU/17mmitmay concern:

Be it known that I, OLIVER S. JENNINGS, a citizen of the United States,and a resident of \Vilkinsbrnrg, in the county of AL legheny and Stateof Pennsylvania, have invented a new andfuseful Improvement in RevolvingFans, of which the fo-llowingis a specification.

My invention relates to rotary electric fans, and it has specialreference to gyratory fans that are adapted to turn on an axis ofrotation while Simultaneously and automatically turnil'lg around an axisof revolution.

One object oi. my invention is to provide a simple, inexpensive andrugged fan structure of theabove-indicated character which shall beauton'iatically driven around its axis of revolution at predeterminedspeeds by the reaction forces set up by the rotation of the fan blades.

Another object. of my invention is to provide convenient means forquickly chang ing the speed of revolution of the fan struc ture.

A further object of my invention is to provide means for maintaining theseveral fan structures constituting my device at equal angular relationswith respect to the support which carries the fan structures.

Figure 1 isa side elevational view of a fan structure embodying myinvention and Fig. 2 is a plan view of the structure shown in Fig. 1.

The device shownin the drawings comprises a bracket 1 rotatablysupported, in any convenient manner, upon a hanger 2 and havingoutwardly and oppositely extending arms 3 and +L. Secured to the outerends of the arms 3 and 4 are bearing members 5 and 6 whichare adapted topivotally support, by means of pivot screws 7, a pair of trunnions 8 and9 in which fan motors 10 and 11 are horizontally pivoted. Thumb screwslQand 13 are provided to secure the fan motors 10 and 11 in adjustedtilted positions around their horizontal pivots. The armature shafts 14and 15 of the fan motors 10 and 11 carry sets of fan blades 16' and 17.The details of the rotatable supportingmeans for the bracket 1. and ofthe fan motors with their fan blades form no part of my presentinvention, and will therefore not. be further described.

As shown in Fig. 1, the bearing members 5 and 6 are slightly inclinedfrom the vertical, the angle of inclination being about five degrees inthe structure shown. This inclination is sufficient to cause the fanmotors to rotate about these inclined pivots by then own weight when thebracket 1 is at rest, and the direction of such inclination causes theend brackets 18 and 19 of the fan motors 10 and 11 to approach thebracket arms 3 and 4, respectively. The trunnions 8 and 9, which carrythe fan motors 10 and 11, are connected by a rod 20, one end of which ispivotally attached, at 21, to the trunnion 9, while the other end ispivotally attached, at 22, to a projection 23 formed on the trunnion 8.The points of attachment of the opposite ends of the rod 20 are sodisposed that they are equidistant from the inclined pivots 7, and thefan motors are caused to move in unison and in the same direction aroundthe inclined pivots 7 Stops 24 are formed on, or attached to, thebearing members 5 and 6 in order to limit the outward pivotal movementof the fan mo tors which is caused by the starting torque of the motors,when they are tilted downward at starting, and also to limit the effectof centrifugal force while the supporting bracket is rotating. Theseforces may, unless prevented by the stops,"or otherwise, rotate the fanmotors far enough outward to bring the thrust axes of the fans up to orbeyond the axis of rotation of the bracket, and the revolution of thebracket may thereby be interrupted or reversed. The starting torque ofthe motors may even throw the motors outward far enough to set thesupporting bracket in rotation in the Wrong direction.

In order to assist centrifugal force in turning the fan motors outwardlyaround their pivots, Iprovide a spring 25 that is maintained in tensionbetween a projection 26 formed on the bracket arm 3 and a screwthreadedhook 2'? which extends through an opening in. a projection 28 formed onthe trunnion S. The tension of the spring 25 may be quickly and easilyvariedby means of a nut 29 disposed upon the screwthreaded portion ofthe hook 27 on the side of the projection 28 opposite to the spring. Asshown in Fig. 2, the force of the spring is exerted along a line thatpasses the motor pivot 7 on the side opposite to the motor, and,tl'ierefore, the effect of, the spring is to arms. In this position, theaxes of rotation erate to turn the fan motors outward around theirrespective inclined pivots in opposition to the force of gravity. Inthusturning the fan motor, centrifugal force is assisted by assist therotation of the fan motor 10 in a counter clockwise d1rect1on,aslndicatcd in Fig. 2. This rotation s transmitted, to the fan motor 9 bymeans of the rod QOwhich,

as stated above, Causes the fan motors to pivotally move in unison.Instead of the spring 2-5, helical springs may be placed around thebearing members 5 and (5, one

end of each spring being in engagementwith the adjacent trunnionsupportand thus assisting theaction' of centrifugal force. In

this arrangement, each spring may be provided with means foradjustlngthe torsion of its coils and thereby varying the pressure "which itexertsiqion the fan trunnion.

i The fan motors 10 and 11 may be supplied with electric energy in anyconvenient manner (not shown) which maybe controlled by means of aswitch button 30.

Then the motors are horizontal, the supporting structure is at rest andthe device is adjusted to revolve at relatively high speeds; the fanmotors will, as stated, above, assume positions in which their rearbrackets approach the adjacent bracket of the two sets of fan blades,that is to say,

the. axes of the armature shafts of the motors, lie on opposites'idesofthe axis of rev,-

olutionof the bracket 2. In" this position,

the tension of thespringio, and the outwardpivotal movementof eachfan-motor is continuousuntil the centrifugal force, to-

I gether with the tension of the spring, a re ex 'actly balanced by. thecomponent of the thrust of the fan blades that tends to rotate the fanmotor ina clockwise direction around its pivot, plus the weight of themotor multiplied by the sine of the angle to which its pivot isinclined. The proportions of the parts and the tension of the spring areso adjusted that, when the axes of the fan motors are horizontal, theseopposing forcesbalance each other when the. motors aresin approximatelythe position shown in Fig. 2. The moment. arm. through which the motorthrust acts in driving the bracket around the axis of the hanger 2 isdeter- .mined by the sum of the perpendicular distances from this axisto the projected axes of rotation of the fan motors. This combineddistance is designated D in Fig. 2 and varies with the retarding forceand downward tilt of the fans. The speed of rotation of the bracket maybe varied by ma-- position of equilibrium will therefore be reachedwhile the bracket is rotating at relatively low speed. The speed ofrotation of the bracket may likewise be increased within wide limits bylessening the tension of the spring In practice, I have found that thespeed of rotation of the bracket may readily be varied between 5 andQOrevolutions per minute.

The forces discussed above are complicated when the fan motors aretilted about the bracket is diminished by the cosine of the anglethrough which the axis of the fan motor is tilted; At the'same time, thehorizontal component of the torque that drives the blades is added to orsubtracted from the turning moment exerted upon the bracket, andisproportional to the sine of the angle of tilt. The direction in whichthe motor torque afi'ects the turning moment exerted upon the bracketdepends upon the direction in which the fan blades revolve. I preferthat the torque of the motors shall assist the rotation of thesupporting bracket, though the device may be adjusted to 0perate withthe torque opposing the rotation of the bracket. Under these operatingcon:

ditions, rotating force acting to. move each fan motor outwardly aroundits inclined pivot is made up of the centrifugal force impressed uponthe motor, plus the tension of the spring, and plus (or'minus) thetorque of the motor multiplied by the sine of the angle through whichthe fan is tilted. When this compound force is balanced bythemotor-turning component of the fan thrust, plus the weight moment ofthe motor multi plied by the sine of the angle of inclination of thepivot, the fan motor will be in stable equilibrium with reference to itspivot.

The downward tilting of the fan motors also causes variations in therelative positions of the parts of the device during its operation. Ifthe motors are tilted through an angle of about 30, and the fan bladesrotate in such a direction, that the torque of the motors assists inrotating the bracket, the torque effect of the motors is just sufficientto rotate the bracket with the fan motors in their position of stable,equilibrium, and

the axes of the fanmotors will then pass through the axis of rotation ofthe bracket, the distance D, Fig. 2, being reduced to zero. When the fanmotors are tilted still further, the torqueeflect is greater than theretarding moment required to be overcome in rotating the bracket, andthis excess torque causes the fan motors to rotate farther outward untilthe backward thrust effect balances; the excess torque effect. The axesof the motors are then on opposite sides of the axis of rotation of thebracket from their positions shown in Fig. 2.

It will be evident that revolving fans constructed in accordance withthe principles discussed above are adapted to revolve ata variety ofspeeds, which may be readily selected and varied bysimple manipulationof the nut 29 which controls the tension of the spring 25, since thistension is the only variable factor of the forces which cause thestructure to revolve when the fan motors are disposed at a giveninclination. It will also be evident that the fan motors are caused tomove in unison by means of the rod 20, which maintains the fan motors inequal an gular relations to the bracket, and that the driving forcesimpressed upon the structure are always regulated in accordance with theresistance to turning offered by the structure.

Numerousstructural modifications may be effected in my device withoutdeparting from the principles of my invention, and it is therefore to beunderstood that my invention comprehends all such changes andmodifications as fall within the scope of the appended claims.

I claim as my invention:

1. The combination witha rotatable supporting member provided with aninclined pivot member, of a rotatable fan pivotally mounted upon thesaid pivot member, where by the said fan tends torotate under theinfluence of gravity around the said pivot.

2. The combination with a rotatable supporting member provided with aninclined pivot for supporting a rotatable fan, of means for opposing thetendency of the said fan to rotate under the influence of gravity aroundthe said pivot.

3. The combination with a rotatable supporting member provided with aninclined pivot for supporting a rotatable fan, of a spring adapted tooppose the tendency of the 'said fan to rotate under the influence ofgravity arounclthe said pivot.

l. The combination with a rotatable supporting member provided with aninclined pivot member, of a rotatable fan pivotally supported by thesaid pivot member and adapted to be pivotally moved thereon bycentrifugal force during the rotation of the said supporting member, anda stop associated with the said supportingmember for limiting the degreeof such ment ofthe said fan.

5. The combination with a rotatable supporting member provided with aninclined pivot member, of a rotatable fan pivotally mounted upon thesaid pivot member and adapted to be pivotally moved in one directionunder the influence of gravity and also adapted to be pivotally moved inthe opposite direction by centrifugal force during the rotation of thesaid supporting member.

6. The combination with a rotatable sup porting member provided with aninclined pivot member, ofa rotatable fan pivotally mounted upon the saidpivot member and adapted to be pivotally moved in one direction underthe influence of gravity and also adapted to be pivotally moved in theoppositc direction bycentrifugal force during the rotation of the saidsupporting member, and means for assisting the action of centrifugalforce in pivotally moving the said fan.

pivotal move- 7. The combination with a rotatable supporting memberprovided with an inclined pivot member, of a rotatable fan pivotallymounted upon the said pivot member and adapted to be pivotally moved inone direction under the influence of gravity and also adapted to bepivotally moved in the opposite direction by centrifugal force duringthe rotation of the said supporting member, and a spring for assistingthe action of centrifugal force in pivotally moving the said fan.

8. The combination with a rotatable sup porting member provided with aninclined pivot member, of a rotatable fan pivotally mounted upon thesaid pivot member and adapted to be pivotally moved in onedirectionunder the influence of gravity and also adapted to be pivotally moved inthe opposite direction by centrifugal force during the rotation of thesaid supportin member, a spring for assisting the action 0 centrifugalforce in pivotally moving the said fan, and means for varying the eifectof the said spring.

9. The combination with a rotatable supporting member provided with aninclined pivot member, of a rotatable fan pivotally mounted upon thesaid pivot member and adapted to be pivotally moved in one directionunder the influence of gravity and also adapted to be pivotally movedinthe opposite direction by centrifugal force during the rotation of thesaid supporting member, and a tension spring secured at one end to thesaid supporting member and at the other end to the said fan, the saidfan and the line along which the tension of the said spring is exertedbeing disposed on opposite. sides of the said pivot member.

10. The combination with a rotatable supporting member provided with aninclined pivot member, of a rotatable fan pivotally mounted upon thesaid pivot member and adapted to be pivotally movedin one directionunder the influence of gravity andalso adapted to be pivotally movedin'the opposite direction by centrifugaliorce during the rotation of thesaid supporting member, a spring secured at one end to the saidsupporting member and at the other, end to the said "fan, and means formanually varying the tensionnof the said spring.

11. The combinationvvith arotat'able supporting member, of two fan'spivotally supported on the said member, and a rod pivoted at itsends tothe saidians."

12. The combination With a rotatable supporting member of tWOfanspivotally supported'on the said member, and a rod pivotally secured,at its ends, to the said fans, the points ofattachment of the ends ofthe said rod to the said fans being substantially equidistant from therespective pivotal axes of the said fans. a i p 13. The combination witha rotatable supportingmember, of two'fans pivotally supported on thesaid member, and a rod pivotally secured, at-its endsg to the said fans,

Copies of this patentmay be obtained for equidistant from the respectivepivotal axes of the 'said'fans and being so dispo'sedivith t relation tothe'said pivoted axes that the said fans are permitted to move pivotallyin the same direction. g

14. The combination with arotatable supporting member provided With aninclined pivot member, of a rotatable fan pivotally supported by the isaid pivot member and adapted to be pivotally moved thereon by thereaction of the said fan and by centrifuif'orce during the rotation ofthe said supporting member, and a stop associated with the saidsupporting member for limiting the degree of such pivotal movement ofthe said fan.

In testimony whereof, I have hereunto subscribed my name this 30th dayof Dec. 1914.

Witnesses:

, R. D. BROWN, B. B; I-IiNns.

five cents each, by addressing the Commissioner of Patents. Washington;I). B.

OLIVER S. JENNINGS.

